The most valuable item in your collection

The post on the Commodore 65 got me thinking about what might be the most valuable item in my own collection. Actually, I have no idea as I don't generally collect them with resale value in mind. None of them get even CLOSE to $20,000 though.
I'm not sure if there are any I would get a four digit number for. Maybe the Lisa 2 or perhaps even the IBM PC as they are both in excellent condition. Getting close to that might be the PET and the Sorcerer. There will be a few there in the high hundreds. Who actually knows until they go to market though! Vintage computer pricing is a fickle thing. I should think about insuring them all separately though as replacement wouldn't be easy.
What's your most valuable piece of hardware?
I'm not sure if there are any I would get a four digit number for. Maybe the Lisa 2 or perhaps even the IBM PC as they are both in excellent condition. Getting close to that might be the PET and the Sorcerer. There will be a few there in the high hundreds. Who actually knows until they go to market though! Vintage computer pricing is a fickle thing. I should think about insuring them all separately though as replacement wouldn't be easy.
What's your most valuable piece of hardware?